Since its discovery as a pulsar in 2000 , the central compact object ( CCO ) 1E 1207.4 - 5209 in the supernova remnant PKS 1209 - 51/52 had been a stable 0.424 s rotator with an extremely small spin-down rate and weak ( B _ { s } \approx 9 \times 10 ^ { 10 } G ) surface dipole magnetic field .
In 2016 we observed a glitch from 1E 1207.4 - 5209 of at least \Delta f / f = ( 2.8 \pm 0.4 ) \times 10 ^ { -9 } , which is typical in size for the general pulsar population .
However , glitch activity is closely correlated with spin-down rate \dot { f } , and pulsars with \dot { f } as small as that of 1E 1207.4 - 5209 are never seen to glitch .
Unlike in glitches of ordinary pulsars , there may have been a large increase in \dot { f } as well .
The thermal X-ray spectrum of 1E 1207.4 - 5209 , with its unique cyclotron absorption lines that measure the surface magnetic field strength , did not show any measurable change after the glitch , which rules out a major disruption in the dipole field as a cause or result of the glitch .
A leading theory of the origin and evolution of CCOs , involving prompt burial of the magnetic field by fall-back of supernova ejecta , might hold the explanation for the glitch .